Russia: Risky diplomatic manoeuvre that could backfire

The defection of Oleg Gordievsky, with his family, sparked a wave of expulsionsBOB COLLIER/THE TIMES

Kicking out foreign intelligence officials is one of the most draconian weapons of diplomacy, a blunt instrument with which to wallop the delicate business of espionage.

Sometimes the weapon backfires, leading to a drawn-out, tit-for-tat conflict that leaves both sides in tatters. Sometimes it has little effect, since spies tend to regenerate and regroup with remarkable speed. But just occasionally a mass expulsion of spooks yields spectacular results.

The British government’s decision to declare 23 suspected Russian intelligence officers personae non gratae comes nearly half a century after the biggest expulsion of spies in history, when 105 Soviet officers were sent packing, a move from which the KGB station in Britain never fully recovered.